Understanding What Shots Do You Take For Anemia

October 11, 2025 •

4 min read

While oral supplements are the first line of treatment for many forms of anemia, approximately 20% of patients experience gastrointestinal side effects with oral iron, making injections a necessary alternative. Therefore, understanding what shots do you take for anemia is crucial for those who cannot tolerate or absorb oral medication.

Quick Summary

Anemia shots provide essential nutrients or hormones directly into the bloodstream, bypassing the digestive system for faster, more effective treatment. The specific type of injection depends on the underlying cause, addressing deficiencies in iron, vitamin B12, or the erythropoietin hormone that stimulates red blood cell production.

Key Points

Iron injections address iron deficiency: IV iron is used for severe iron-deficiency anemia, malabsorption problems (like IBD, celiac disease), or when oral iron isn't tolerated.
Vitamin B12 shots treat B12 deficiency: This treatment is necessary for pernicious anemia and other malabsorption issues to ensure proper B12 absorption.
EPO shots stimulate red blood cell production: Erythropoietin-stimulating agents (ESAs) are given to counteract anemia caused by kidney disease or specific medical treatments.
Shots are used when oral options fail: Injections offer a fast, highly-absorbable treatment alternative for patients who can't tolerate or don't respond well to oral supplements.
The type of shot depends on the cause: The correct injectable treatment is determined by the specific type of anemia, which requires an accurate diagnosis from a healthcare provider.

Different Types of Shots for Anemia

Treatment for anemia depends on its root cause. For certain conditions, injections are more effective or the only viable option. The primary types of shots for anemia include intravenous (IV) iron, vitamin B12 injections, and erythropoietin-stimulating agents (ESAs).

Iron Injections for Iron-Deficiency Anemia

Iron-deficiency anemia is the most common type of anemia, resulting from insufficient iron to produce hemoglobin. While oral iron supplements are standard, injectable iron, often delivered via IV infusion, is used for patients who meet specific criteria.

Commonly used IV iron products include:

Ferric carboxymaltose (brand name Injectafer)
Ferumoxytol (brand name Feraheme)
Iron dextran (brand names INFeD, Dexferrum)
Iron sucrose (brand name Venofer)

Reasons for choosing iron injections include:

Intolerance to oral iron: Severe gastrointestinal side effects like nausea, stomach pain, or constipation.
Malabsorption issues: Conditions such as inflammatory bowel disease (IBD), celiac disease, or post-bariatric surgery can prevent proper iron absorption.
Chronic kidney disease (CKD): Patients with CKD, especially those on dialysis, often require IV iron to supplement erythropoietin-stimulating agent therapy.
Severe or rapid iron repletion: In cases of severe anemia or before major surgery with high blood loss, injections can raise iron levels faster than oral supplements.

Vitamin B12 Shots for Deficiency Anemia

Vitamin B12 deficiency anemia, which includes pernicious anemia, occurs when the body cannot absorb enough B12 from the digestive tract. In these cases, regular vitamin B12 injections are necessary to bypass the faulty absorption mechanism.

Key aspects of B12 shots:

The most common injectable form is hydroxocobalamin, which is preferred over cyanocobalamin in some regions as it stays in the body longer.
Treatment typically begins with a course of frequent injections (e.g., every other day for two weeks) to restore levels, followed by maintenance shots every few months for life.
Regular shots are essential to prevent the return of anemia and potential permanent nerve damage.

Erythropoietin-Stimulating Agents (ESAs)

Anemia can also be caused by a lack of the hormone erythropoietin (EPO), which signals the bone marrow to produce red blood cells. This is common in patients with chronic kidney disease, as the kidneys naturally produce EPO. ESAs are synthetic versions of EPO administered via injection to boost red blood cell production.

Who needs ESA shots:

Patients with chronic kidney disease.
Patients undergoing certain types of chemotherapy.
Patients with anemia related to HIV therapy with the drug zidovudine.

Oral vs. Injectable Anemia Treatment: A Comparison


Feature	Oral Iron Supplements	Injectable Iron (IV)	Vitamin B12 Shots	ESA Shots (e.g., epoetin alfa)
Best for	Mild-to-moderate iron deficiency with good absorption	Severe iron deficiency, malabsorption, or chronic kidney disease	Pernicious anemia and B12 malabsorption issues	Anemia due to lack of EPO from chronic kidney disease or chemotherapy
Absorption	Can be limited by food, disease, or side effects	100% bioavailability, directly into the bloodstream	Bypasses the digestive system for direct delivery	Stimulates natural production via injection
Speed of Action	Slower; can take weeks or months to see significant improvement	Faster; can rapidly increase iron stores and blood cell production	Quick initial effect, with long-term maintenance required	Gradually increases red blood cell count over several weeks
Side Effects	Gastrointestinal upset (nausea, constipation, cramps) is common	Potential allergic reactions, flushing, headache, or low phosphate levels	Generally well-tolerated, some mild side effects possible	Can cause high blood pressure, fever, or pain at injection site
Convenience	Easy to take at home, but often requires consistent daily dosing	Administered in a clinical setting; fewer, larger doses needed	Can be self-administered at home after training or given at a clinic	Typically given at a clinic or dialysis center; can be self-administered

Who Needs Anemia Shots?

The decision to use injectable anemia treatment is based on a patient's individual needs and medical history. Oral supplements are almost always tried first for iron and B12 deficiencies, but injections are reserved for more complex cases.

Patients who often require anemia shots include:

Those with gastrointestinal disorders like inflammatory bowel disease (IBD) or celiac disease, which impair nutrient absorption.
Patients who have undergone gastric surgery, such as bariatric surgery, which affects the body's ability to absorb iron and B12.
Individuals with severe anemia requiring rapid replenishment of iron, such as before major surgery or in cases of significant blood loss.
People with chronic kidney disease whose kidneys don't produce enough erythropoietin.
Patients with pernicious anemia, a condition where the body cannot produce a substance needed to absorb vitamin B12.
Some cancer patients receiving chemotherapy and HIV patients taking zidovudine.

Conclusion

Injectable treatments for anemia are powerful and effective options when oral supplements are not sufficient or appropriate. The specific type of shot—whether it is intravenous iron, vitamin B12, or an erythropoietin-stimulating agent—is determined by the underlying cause of the anemia. While more invasive than oral tablets, injections ensure that the necessary components are delivered directly and efficiently into the body to support red blood cell production. It is important to work with a healthcare provider to receive a proper diagnosis and treatment plan, as the type of anemia dictates the correct course of action. Following medical guidance for injectable treatments is crucial for restoring health and managing the condition effectively. For more in-depth information, resources from reliable medical sources like the National Institutes of Health can be useful.

Frequently Asked Questions

Anemia shots are typically necessary when the underlying cause is due to poor absorption in the gut, intolerance to oral supplements, or when the anemia is severe and requires rapid correction. This includes cases of pernicious anemia, severe iron deficiency, and anemia caused by chronic kidney disease or certain cancer treatments.

Pain associated with anemia shots varies. IV iron infusions are generally well-tolerated, but B12 injections can cause some soreness or bruising at the injection site, similar to any other shot. Pain is usually temporary and mild.

The duration depends on the cause of the anemia. For pernicious anemia, lifelong B12 injections are usually required. For severe iron deficiency, a course of IV iron might be needed for a few weeks, but long-term treatment depends on the underlying issue. ESA therapy for chronic kidney disease may also be ongoing.

For certain conditions, such as B12 deficiency, patients can be trained to self-administer injections at home. However, IV iron infusions and initial doses of ESAs typically require administration by a healthcare professional in a clinic or hospital setting.

Side effects differ by treatment. IV iron can cause headaches, flushing, or low blood phosphate levels. B12 injections are generally safe, while ESAs may lead to high blood pressure. A healthcare provider can explain potential side effects specific to your treatment.

Diagnosis typically involves a blood test to check hemoglobin, iron levels, and B12 levels. A doctor will also consider your symptoms and medical history to determine the specific type of anemia and whether an injectable treatment is the best course of action.

The terms are sometimes used interchangeably, but IV iron is often delivered via an infusion, which is a slow drip into a vein over a period of time. Older forms of iron could be given as intramuscular shots, but IV infusions are now the preferred method.